Californians with a current identification card can skip straight to Step 4!
Step 1) Reside in California
Step 2) Schedule an appointment at any Calif. DMV location
Step 3) Decide if you want a California Driver License or Identification Card. I'd recommend the latter if you're still in school/military; and don't forget that if you get the DL, you also have to get in-state license plates and insurance.
Step 4) Learn about qualifying conditions, from Calif. H&S 11362.5:
Californians have the right to obtain and use marijuana for medical purposes where that medical use is deemed appropriate and has been recommended by a physician who has determined that the person's health would benefit from the use of marijuana in the treatment of cancer, anorexia, AIDS, chronic pain, spasticity, glaucoma, arthritis, migraine, or any other illness for which marijuana provides relief.
Step 5) With the paper DMV receipt, you can now visit your favorite local pot doc. If, in the doctor's opinion, she agrees that cannabis can improve your quality of life, you'll get yourself a Physician's Recommendation.
Step 6) Wait for your California ID to arrive (you must have this to enter a dispensary)
Step 7) Become a member of your local dispensary. I recommend these place in the bayarea: Angel's Care (south bay); Vapor Room (SF - Haight); Harborside (Oakland)
Step 8) Awwwwwww Yeah... you'll know what to do (buy piece, acquire friends, eat munchies)